Interactions between the gene products of pma1 encoding plasma membrane H(+)-ATPase, and pdr1 controlling multiple drug resistance in Saccharomyces cerevisiae.

Abstract

In Saccharomyces cerevisiae, the pma1 mutations controlling the vanadate resistance of the H(+)-ATPase activity from the plasma membrane, map on chromosome VII in the vicinity of pdr1 mutations controlling multiple drug resistance. However, the pma1-1 mutants exhibit a genotype and a multidrug resistant phenotype quite different from those obtained for pdr1 mutants. Quantitative modifications of cycloheximide and N,N'-(p-xylylidene)-bis-aminoguanidine-2HCl resistance are observed in diploids containing the pma1 and pdr1 genes in trans configuration. Each of the pdr1 mutations interacts with pma1 as shown by a decrease in the ATPase activity in pdr1/pma1 diploids. The in vitro resistance of ATPase activity to vanadate is totally or partially suppressed in pdr1 mutants in haploid double mutants. These results suggest that the expression of PMA1 might be controlled by the PDR1 gene product.